Compensating apparatus for elevator hoisting roping



Jan, 9, 1951 s. e. MARGLES 2,537,075

COMPENSATING APPARATUS FOR ELEVATOR HOISTING .ROPING Filed Oct. 9, 19482 Sheets-Sheet l M 6 INVENTOR ATTORNEY a, e. MARGLES Jan. 9, 1951COMPENSATING APPARATUS FOR'ELEVATOR HOISTING ROPING Filed Oct. 9, 1948 2Sheets-Sheet 2 .4! Al I 40 SM GMW INVENTOQ I AT TOR NET Patented Jan. 9,1951 um STATES; PATENT OFFICE.

GOMPENSA'IING APPARATUS F03, ELEVATOR HQISTING ROPING Sannnet- GustaveMargles, Brooklyn; N Ya, as

signer to Otis Elevator Company, New York, N. Y.',. av corporation ofNew Jersey Application October 9, 1948, sen-rains. 53547 (CL R F -22)il' Gl-aims;

The invention relates to compensating apparatus for elevator hoistingroping,

In elevatorinstallations of'the traction type, the elevator carand'counterweight'are suspended by hoisting ropes which pass over ahoisting" sheave at the top ofthe hoistway, It is usual'i'n suchinstallations to compensate for the unbalanced'weight of the hoisting,roping as the car andcounterweight' move up and down in the elevat'orhoistway; In most of" these installations this compensation'is effectedby roping which is suspendedifrom the car and" counterweight, thisroping passing around a sheave,, termed' 8;, compensating sheave, ,at'the-bottom .ofthe hoistway. In certain installationschainjcompensationhas been utilized: In installations where, compensa-.-tion is provided, it'is desirable to make the connections to the carand" counterweight at such points as to minimize thrusts on the guideshoes.v

Existing conditions may make it necessary in an elevator installation tohave ashallow pit below'the lower terminalfloorh Thus where compensatingsheaves are employed,1 it1is desirable thatthey be' arranged" to utilizea minimum of vertical space.

There are-certainadvantages invchain compen-. sation; One ofthe moreimportantlofjthesead' vantages resides in the low costl However, chaincompensation has not heretofore been provided in any except slowspjeedinstallations because of the noise of the chain in operation,

One'feature ofthe" invention i'sito'provide chain compensationwhich isquiet in operation.

Another feature of the invention i's tO provide chain compensation ofthis character which is suitable for: installations having shallow pits.

Still anotherfeature of the invention is to provide' a compensatingarrangement in which the compensation is efiectedsoas to minimize anythrust on the guideshoes for the car and'counterweight.

Other features and advantages will become apparent fromthefollowingdescription and appended claims;

In carrying out the inventi'on according to the arrangement which willbe -described; the compensation isefiected by a pair of chains, eachsecured at one end to'the' elevatorcar and extend ing downwardl'yintothe 'hoistway pit and thence upwardly to the counterweighttowhichitsother end is connected; Atithe bottom each chain passes aroundapair' of small sheaves mounted in horizontally spaced relationship" in'a frame" arranged to' permitx vertical movement. Thesheavesareiprovidedwithzaifacing of soundidead Y quired' for the"compensating'" apparatus.

china resilient non meta'llic material grooved to" accommodate thechain; therebyminimizing any noise of chain operation: Also the smallsheaves minimize the amount of vertical pit" room re- The chains areconnected to the car" and counterweight with respect to the centers ofgravity thereofso-as to' minimizeany' thrusts on thegui'd'e Also theconnections are made so as toshoes: enable one buffer to be usecl'for"thecarandone' for the counterweight, witheachbufieracting in the line"of" the center of gravity of" the body" for which it is provided; Thisis' effected by connecting' thechains toeachbodyone on each side of" thebuffer for thatbody and symmetrical with re spect to the center ofgravity ofthe'body: Variations' may be madein' certain instances in caseof the car to' balance the travelling cable's.

In the drawings Figure 1 is a schematic trimetric' representation of anelevator installation embodying the invention;

Figure 2 is a plan view of the compensating sheaves'and frame for one ofthe compensating" chains;

Figure 3"is a View of thesame" in elevation; il-

lustrating also the-connection of the chain to the car and counterweightFigure 4' is a viewi'n section taken along; the line i -4 of Figure3;"and' Figure 5 is a view'with parts in section ofjone of thecompensating'sheaves.

Referring tohigure 1; the elevator car it) and ing these members to'astop should'they'continue into the elevator pit during' downwardmovement: The car buffer is mounted on the'fioor' iiiof the pit whereasthe counterweight bulfer" is carriedbythe counterweightitsel-ffiCompensation for the unbalanced weight (ii-"theropes is provided bytwospaced chains 28 and 21;

Each compensating chain extends downwardly" from the'elevator car arounda pair of sheaves- 22 and 230i atensioning devicez i-in theel'evator pitand thence. upwardly to the counterweight;

Thetensioning devices-are ofthe same construction. The construction ofone of'thesetension ingdevices and the manner of connectingacompensating-ichain' to the car and-counterweight is 3 illustrated inFigures 2, 3, 4 and 5 to which attention may now be had.

The chain is illustrated as of a straight link construction. At the carthe chain is connected through an S hook 25 and hitch 26 to a plate 27.This plate is'secured to the plank channels 28 mounted beneath the carplatform 39 and together with upright channel 3! forming part of the carframework. The other end of the chain is secured to the counterweightthrough a hitch 32 and anchor bracket 33 bolted to the counterweightframe.

The tensioning device 24 comprises a frame 3d having a pair of sideplates 35. These side plates are secured in spaced relationship by meansof cross plates 36 secured to L-shaped angles 31 in turn secured to theside plates. These side plates support the shafts 38 for thecompensating sheaves 22 and 23. These shafts extend in spacedrelationship crosswise of the side plates and are secured to the frameby nuts 41] on the threaded ends of the shafts. The spacing of theseshafts is determined by the character of the installation. Arranged oneach shaft is a pair of ball bearings 4| on which the comepnsatingsheave is mounted. Each sheave has a grooved rim 42 provided with afacing 43 of sound deadening resilient non-metallic material such asrubber. Neoprene has been found satisfactory because of its oilresistant properties, espec-ally in View of the fact that it isconsidered desirable to oil the chains. The neoprene is vulcanized tothe rim and formed with a groove M to accommodate the chain. Bolts 45 ateach end of the frame are provided to retain the chain in the grooves ofthe compensating sheaves.

Guides 511 and iii are provided on the outside of each of side plates 35at the top and bottom thereof. These guides cooperate with verticalguide rails 52 and 53 to guide the frame and therefore the compensatingsheaves 22 and 23 for vertical movement. These guide rails are securedby means of L-shaped brackets 55 to a channel member 56 extendingcrosswise of the pit. At their upper ends, the guide rails are bracedthrough angle members 57 and 58 fastened tostructuer not shown at thesides of the pit. The tensioning frame and sheaves have sufficientweight in themselves to maintain the chain taut.

A switch 6:] is mounted on the guide rail 52 by means of a bracket 6|.This switch is provided with an operating arm 62 adapted to be struck bythe arms 63 of spaced angles 64 mounted on the tensioning frame. Withthis arrangement should the tensioning frame move downwardly beyond acertain point or upwardly beyond a certain point the switch is operated.This switch is arranged to cause the stopping of the hoisting motorshould this operation take place. Thus any danger of the tensioningdevice resting on channel 55 or being struck by the car or counterweightis minimized.

The compensating chains 20 and 2| are connected to the car andcounterweight so as to be symmetrical with respect to the centers ofgravities of the bodies. This obviates side thrusts on the guide shoeswhich is especially important when rubber tired roller guides areemployed. One arrangement is illustrated in Figure 1. In thisarrangement, connection is made to the counterweight so that theverticalportions of the chains suspended from the counterweight are in a planeparallel to the front of the counterweight and through the center ofgravity of the counterweight, with the chains equally spaced on eachside of the center of gravity. Also the chains are connected to the carso that the vertical portions suspended from the car are in a planeparallel to the plane of the chains suspended from the counterweight andthrough the center of gravity of the car, with the chains equally spacedon each side of the center of gravity. The connection of the chains tothe car may be made off the physical center of the car where the cardoor and door operating mechanism throws the actual center of gravity tothe door side of the physical center. Also, it may be desirable toconnect the chains somewhat off the center of gravity to provide amoment to balance a moment due to the connection of the travellingcables to the car.

It is important that the buffer for the counterweight apply its force atthe center of gravity of the counerweight. This is accomplished byspacing the points of connection of the chains to the counterweightequidistant from the center of gravity of the counterweight whichenables the counterweight buifer to be mounted in line with the centerof gravity of the counterweight. It is also important that the bufferfor the car apply its force at the center of gravity of the car. This issimilarly accomplished by spacing the points of connection of the chainsto the car equidistant from the center of gravity of the car whichenables the car buffer to be mounted in line with the center of gravityof the car.

With the above construction chain compensation is provided which isquiet in operation. Also tensioning apparatus is provided which issuitable for shallow pits. In addition the compensation is effected soas to obviate side thrusts on the guides. Also the compensating framesfor the chains enables weights to be added where it is desirable toincrease the traction on the hoisting sheave.

As many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An elevator installation wherein the elevator car and itscounterweight are suspended by hoisting roping and wherein apparatus isprovided for compensating for the unbalanced weight.

of the hoisting roping, characterized by the fact that said compensatingapparatus comprises a chain connected at one end to the car and at theother end to the counterweight and a tensioning device for the chain atthe bottom of the elevator hoistway, said tensioning device including asheave having a facing of sound deadening resilient non-metallicmaterial around which the chain passes.

2. An elevator system comprising, an elevator car, a counterweight, ahoisting sheave, hoisting roping connected to said car and counterweightand extending over said hoisting sheave, a compensating chain for saidhoisting roping connected at one end to the car and at the other end tothe counterweight, and a tensioning device for said compensating chainincluding a sheave with a rubber tire around which the chain passes.

3. An elevator installation wherein the elevator car and itscounterweight are suspended by hoisting roping and wherein apparatus isprovided for compensating fo the unbalanced weight of the car, acounterweight, a hoisting sheave, hoisting roping connected to said carand counterweight and extending over said hoisting sheave, acompensating chain for said hoisting roping connected at one end to thecar and at the other end to the counterweight, and a tensioning devicefor said compensating chain including a pair of spaced rubber tiredsheaves around which the chain passes and a frame for mounting saidrubber tired sheaves.

5. An elevator installation wherein the elevator car and itscounterweight are suspended by hoisting roping and wherein apparatus isprovided for compensating for the unbalanced weight of the hoistingroping, characterized by the fact that said compensating apparatuscomprises a pair of spaced chains, each suspended at one end from thecar and at the other end from the counterweight, and a tensioningdevicefor each chain at the bottom of the elevator hoistway, each tensioningdevice including a pair of horizontally spaced sheaves around which thechain passes, each having a rubber tire grooved to accommodate thechain.

6. An elevator system comprising, an elevator car, a counterweight, ahoisting sheave, hoisting roping connected to said car and counterweightand extending over said hoisting sheave, a air of spaced compensatingchains for said hoisting roping, each connected at one end to the car ina given relationship to the center of gravity of the car and at theother end to the counterweight in a given relationship to the center ofgravity of the counterweight, and a tensioning device for eachcompensating chain, each tensioning device including a pair of groovedrubber tired compensating sheaves around which the chain passes and aframe for mounting said compensating sheaves in horizontal spacedalignment.

'7. An elevator installation wherein the elevator car and itscounterweight are suspended by hoisting roping and wherein apparatus isprovided for compensating for the unbalanced weight of thehoistingroping, characterized by the fact that said compensatingapparatus comprises a pair of chains extending from the car to thecounterweight, said chains being connected to the car in spacedrelationship and symmetrical with respect to its center of gravity andbeing connected to the counterweight in spaced relationship andsymmetrical with respect to its center of gravity and a tensioningdevice for each chain at the bottom of the elevator hoistway, eachtensioning device including a pair of grooved neoprene tiredcompensating sheaves around which the chain passes and a frame formounting said compensating sheaves in horizontal alignment and spaced sothat the chain hangs vertically from the car and counterweight.

8. An elevator system comprising, an elevator car, a counterweight, ahoisting sheave, hoisting roping connected to said car and counterweightand extending over said hoisting sheave, a pair of compensating chainsfor said hoisting roping extending from the car to the counterweight,means for connecting said chains to the counterweight in a planeparallel to the front of the counterweight and through its center ofgravity, with the chains equally spaced from the center of gravity ofthe counterweight, means for connecting said chains to the car in aplane parallel to the plane of connection of the chains to thecounterweight, with the chains equally spaced from the center of gravityof the car, a tensioning device for each chain at the bottom of theelevator hoistway, each tensioning device including a pair of groovedrubber tired compensating sheaves around which the chain passes and aframe for mounting said sheaves in horizontal alignment and spaced sothat the chain hangs vertically from the car and counterweight, andmeans for guiding each tensioning device for vertical movement.

9. An elevator installation wherein the elevator car and itscounterweight are suspended by hoisting roping, wherein a buffer isprovided for the car positioned to act in the line of the center ofgravity of the car and a buffer is provided for the counterweightpositioned to act in the line of the center of gravity of thecounterweight, and wherein apparatus is provided for compensating forthe unbalanced weight of the hoisting roping, characterized by the factthat said compensating apparatus comprises a pair of chains extendingfrom the car to the counterweight, said chains being connected to thecar so as to be equally spaced one on each side of said car buffer andbeing connected to the counterweight so as to be equally spaced one oneach side of said counterweight buffer, a tensioning device for eachchain at the bottom of the elevator hoistway, each tensioning deviceincluding a pair of grooved neoprene tired compensating sheaves aroundwhich the chain passes and a frame for mounting said compensatingsheaves in horizontal alignment and spaced so that the chain hangsvertically from the car and counterweight, and means for each frame forguiding it for vertical movement.

SAMUEL GUSTAVE MARGLES.

REFERENCES CITED The following references are of record in the file ofthis-patent:

UNITED STATES PATENTS Number Name Date 1,789,008 Lindquist Jan. 13, 19311,944,772 White Jan. 23, 1934 2,295,381 Bouton Sept. 8, 1942

